The present invention relates to an apparatus for dispensing a foam comprising a mixture of a foamable liquid and air. Foam pumps are commonly used to dispense a foamable liquid from a rigid container. In such applications, a foam pump is typically mounted in the neck of a rigid container and employs a dip tube extending from a liquid inlet of the foam pump to the bottom of the container. A manually depressible nozzle is typically attached to the liquid outlet of the foam pump for dispensing the liquid-air mixture. Such foam pumps often employ an air cylinder and a liquid cylinder that are concentrically arranged but axially offset. The axial offset between the liquid cylinder and the air cylinder increases the axial length of the pump. An exemplary, commercially foam engine of this type is descried in U.S. Pat. No. 6,053,364, incorporated herein by reference in its entirety.
U.S. Pat. No. 8,336,740 discloses a system and method for adapting such prior art foam pumps for use in a bag-in-box type fluid dispenser. In a bag-in-box dispenser, the fluid reservoir is positioned above the pump and the pump is inverted such that the liquid outlet of the pump is positioned below the liquid inlet of the pump. However, because of the axial offset between the air cylinder and the liquid cylinder, such pumps generally have a high profile and extend into the bag containing the liquid to be dispensed. As such, with such pumps, measures must be taken to allow the liquid pump inlet to communicate with the bottom of the fluid reservoir to avoid product waste. The aforementioned U.S. Pat. No. 8,336,740 is incorporated herein by reference in its entirety.
In addition, such fluid reservoirs are typically plastic bags constructed from flexible plastic film, which are configured to allow the pressure within the bag to equalize with the ambient air pressure to avoid the need to vent the fluid reservoir. Such plastic bags are prone to puncture and the prior art high profile pumps extending into the flexible bags are a source of trauma to the bags during transport and handling.
Furthermore, leakage is of special concern for foam pumps that are employed in an inverted orientation. In such inverted applications, the fluid source is located above the pump. Thus, if the pump piston were to stick or liquid outlet valve were to otherwise fail, catastrophic leakage could occur resulting in not only product waste but also a potentially hazardous condition, e.g., should the liquid product leak onto the floor.
The present disclosure contemplates a new and improved foam pump and dispenser which overcome the above-referenced problems and others.